LISTSERV at the University of Georgia
Menubar Imagemap
Home Browse Manage Request Manuals Register
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (September 2005)Back to main SPSSX-L pageJoin or leave SPSSX-L (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Fri, 30 Sep 2005 21:37:52 +0100
Reply-To:     Josh Johnson <joshjohnson88990@yahoo.co.uk>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Josh Johnson <joshjohnson88990@yahoo.co.uk>
Subject:      Stability estimation: test-retest alpha reliability coefficient
Content-Type: text/plain; charset=iso-8859-1

Hi all,

A question regarding test-retest reliability/stability calculation-

For the simple case of, for example, n respondents measured twice each (say, a month apart between administrations) on only one test/question. The calculation of the coefficient alpha seems to me straight forward in SPSS-

àSelect the two variables (the test and retest) to the variable box, àselect alpha, two way mixed (consistency) as the model.

(This is assuming the n respondents are a random sample of the larger population but the one question/test is the only item we are interested in and not a sample of a larger group of questions)

However how does one calculate the coefficient alpha when more then one measurement/question is asked for each respondent? For example a case where 20 questions are asked twice (test-retest)- is there an overall alpha I can calculate or am I confined to calculating separate alpha’s for each question? Assuming again that the respondents are a random sample and the 20 questions are fixed (not a sample of a larger group of questions I am interested in asking)

Any advice, references will be greatly appreciated.

Thanks in advance,

Josh

--------------------------------- Yahoo! Messenger NEW - crystal clear PC to PC calling worldwide with voicemail


Back to: Top of message | Previous page | Main SPSSX-L page